Method of securing pulleys or crank-disks to shafts



(No ModeL) W. A. BOLE.

METHOD OF SECURING PULLEYS OR CRANK DISKS TO SHAPTS. No. 314,788. Patented Mar. 31, 1885.

\NITNESSES;

A INVENTOR ww/u WWW Z7M@fl/ ATTOR N. PETERS, Phokrljlhngrlphnr. Wnhingion, D. C.

Warren STATES W'ILLIAM A. BOLE, OF PITTSBURG, PENNSYLVANIA.

METHOD OF SECURING PULLEYS OR CRANK-DISKS TO SHAFTS.

SPECIFICATION forming part of Letters Patent No. 314,788, dated March 31, 1885.

Application filed December 16, 1884. (No model.)

To aZZ whom, it may concern.-

Be it known that I, WILLIAM A. BOLE, a citizen of the United States, residing at Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented or discovered a certain new and useful Improvement in Securing Pulleys or Crank-Disks to Shafts, of which improvement the following is a specification.

In the accompanying drawings,which make part of this specification, Figure 1 is an end view of a crank-disk and crank, illustrating the application of my invention; Fig. 2,asectionalelevation at the line we of Fig. 1; Fig.

'3, a section at the line y yof Fig. 1; Fig. 4, an

end view of a pulley fixed upon a shaft in accordance with my invention, and Fig. 5 a transverse section at the line z a of Fig. 4..

My invention is an improvement upon that for which Letters Patent of the United States No. 297,313, dated April 22, 188 l,were granted and issued to the Westinghouse Machine Company, as assignee of Harris Tabor; and its object is to insure the firm connection of a crankdisk or pulley to a shaft or crank-arm when united therewith by being cast thereon.

To this end my improvement, generally stated, consists in a novel method of securing a crank-disk or pulley to a shaft by casting the same upon and around said shaft and around the outer side of a loose adjustable key fitted longitudinally therein, and thereaftertightening said key, as hereinafter more fully set forth.

It has been found in practice thatin uniting a cast=metal member to another which has been previously formed, eitherlof cast or wrought metal, by casting the former around the latter, as in Letters Patent No. 297,313, above referred to, such connection of the two as will be perfectly exempt from looseness is not in all cases attainable, owing to the contraction of the new casting in the solidification of the metal of which it is composed, and the tightening or clamping together of the two by the usual mechanical expedient of keying is inconvenient and objectionable by reason of the fact that the new casting chills and becomes so hard on its surface adjoining that of the older member that the cutting and proper fitting of keyways are difficult,if not impracticable. Under my invention I dispense with the operation of cutting keyways in the new casting, while attaining a firm and tight connection by the wedging action of a perfectlyfitting and readily-adjustable key.

In the practice of my invention alongitudinal recess or keyway, 3, of which there may be one or more, as desired, is caster otherwise formed in the periphery of the shaft 1, (or of the crank-arm 2 of said shaft, as the case may be,)to which the pulley, crank-disk, balancewheel, or other member is to be attached, said recess being substantially parallel with the axial line of the shaft, and, it upon the crankarm, extending p1 eferably from one face there of to the opposite facer Akey, 4, corresponding in width with and of aboiit the same length as the keyway, and tapered or inclined from one end to the other, is fitted with the capacity of longitudinal movement in the keyway, thekey projecting above the keyway throughout its length, to engage the casting subsequently to be formed. The shaft, with the inserted key or keys, is next set in proper position in molding-sand, in which, by the use of a suitable pattern, a mold is formed. The disk or pulley 5 is then cast in said mold, completely surrounding the periphery of the crank or shaft and projecting portion of the key or keys. After the solidification and contraction of the cast metal, the key is driven tightly to a bearing, and any looseness which might otherwise result from the contraction of the casting will be effectually prevented. The inconvenience and expense of fitting the key to the disk are thus obviated, and the draft of the key on the disk is exerted against a surface with which the key is accurately in correspondence.

Itwill be obvious that my invention may be similarly applied in the connection of members other than those selected for illustrationas, in many instances, where it is desired to combine a casting and forging withoutexpensive fitting-such applications being within the ordinary ability of those skilled in the art to which my improvements relate. Further, I am aware that a disk connected to a crank by being cast thereon, and a disk or pulley connected to a shaft by being keyed thereto, as also an expansible split sleeve cast around a removable core which acts as the support for a key and a dividing piece, were known at e the date of myinvention, and such, therefore, ing crank-disks, pulleys, &c., to shafts,which I distinctly disclaim. consists in first fitting a wedging-key in a lon- My invention differs from the construction gitudinal recess in the periphery of the shaft 20 last referred to in the essential particular that or of a crank-arm thereon, then casting the 5 I combine, in the connection of the crank or disk-or pulley upon and continuously around shaft and disk, a shrink fit, due to the conthe shaft and key, and finally driving the key traction of the casting", with a wedging fit efto a tight bearing, after the solidification and fected by the draft of the key upon a contincontraction of the casting, upon the member 25 uous' body of metal, while in the former case which it permanently incloses, substantially IO the connection of the sleeve and shaft is efas set forth.

fected only by the action of the key against In testimony whereof I have hereunto set clamping-bands applied subsequently to the my hand.

casting-of the sleeve, and no attachment by I contraction of the metal is contemplated or WILLIAM BOLE' I5 obtainable. Witnesses:

claim herein as my invention- J. SNowDnN BELL, The improvement in the method of secur- FRANK W. HUGHEY. 

